Stable cosmetic composition comprising a self-tanning agent

ABSTRACT

Stable topical compositions having a pH of from 3.5 to 4.5 comprising a self-tanning agent, a polymer and a polyhydric alcohol humectant. The compositions of the present invention are highly stable, and deliver high levels of active self-tanning agent to the skin upon topical application.

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention is directed towards cosmetic compositionscomprising a self-tanning agent having good shelf stability, goodapplication characteristics and imparting excellent skin colourationwithout unacceptable orange discolouration.

BACKGROUND OF THE INVENTION

[0002] A wide variety of cosmetic compositions containing self-tanningagents have been used to increase the pigmentation of the skin. Thesecompositions have been used to create artificial tans, bronzing the skinin a similar fashion to exposure to the sun. These compositions aretypically quite unstable, having poor shelf life. This is thought to bedue to the highly reactive nature of the self-tanning agents therein.

[0003] The prior art teaches several solutions to the problem ofstability of self-tanning agents in cosmetic compositions. U.S. Pat. No.6,231,837 B1 teaches the use of polyethoxyglycols such as ethoxydiglycoland polyols to stabilise self-tanning agent-containing compositions. WO98/00098 teaches the combination of self-tanning agents and cross-linkednon-emulsifying siloxane elastomers to form stable emulsions. U.S. Pat.No. 6,197,287 discloses anionic polymers and compositions comprisingthem, including self-tanning agents. However, these solutions are notentirely satisfactory at maintaining the stability of self-tanningagent-containing formulations or have other disadvantages such as poorskin feel when topically applied.

[0004] It is desirable to provide stable cosmetic compositionscomprising a self-tanning agent to provide a unique level of skintanning that lifts the skin tone. Furthermore, it is desirable toprovide a cosmetic composition comprising both self-tanning skincolouring agents and chronic skin care actives that act synergisticallyto maximise skin tone enhancement. It is further desirable to includechronic skin regulating agents in the compositions of the presentinvention to improve the skin barrier and so minimise any areas of dryor compromised skin. This is desirable as dry skin areas have unevenuptake of colour resulting in a blotchy or patchy result.

[0005] A supplier brochure by SEPPIC (XP-002260687), entitled “Simulgel™NS—An emulsifying/thickening polymer . . . for New Sensations” disclosea self-tan gel-cream composition comprising 5% by weight Simulgel NS and2.00% by weight dehydroxyacetone, but no humectant.

[0006] A summary of a poster by T. Kurz (P043, “The Color of DHA Tan”)presented at an International Federation of Societies of CosmeticChemists (IFSCC) conference in Venezia (1994) relates to thepossibilities to influence the hue of a DHA tan. The influence of havinga moisturizer is discussed, and according to this document, “addition of10% moisturizer does not increase the intensity of the tanning, it evenseems to lead to a slight reduction of it”. Different results wereobtained at a level of 20% moisturizer.

SUMMARY OF THE INVENTION

[0007] The present invention is directed to cosmetic compositionscomprising:

[0008] a) a self-tanning agent conforming to the general formula;

[0009] wherein R₁ is H, CH₂OH, CHOHCH₂OH, CH(OH)CH(═O), CH(OCH₃)CH(═O),CH(NH₂)CH(═O), or CH(NH-Phenyl)CH(═O); and R₂ is H or CH₂OH; and

[0010] b) a cross-linked anionic polyelectrolyte polymer, saidpolyelectrolyte polymer comprising;

[0011] i) from 58.7% to 89.9999% by weight of the polyelectrolytepolymer of a monomer comprising a strongly acidic function;

[0012] ii) from 9.9999% to 40% by weight of the polyelectrolyte polymerof at least one neutral monomer comprising a hydroxy alkyl acrylate; and

[0013] iii) from 0.0002% to 1.3% by weight of the polyelectrolytepolymer of a diethylenic or polyethylenic cross-linking agent;

[0014] c) a polyhydric alcohol humectant;

[0015] said composition further having a pH of from 3.5 to 4.5.

[0016] The invention preferably comprises from 5 to 30% by weight of thepolyhydric alcohol humectant, more preferably from 5 to 15%.

[0017] The present invention is further directed towards providing skincare kits, methods of regulating skin condition and methods ofmanufacture of the cosmetic composition.

[0018] The compositions of the invention are stable, useful for topicalapplication and for providing essentially immediate (i.e. acute)improvement in skin appearance following topical application. Withoutbeing limited by theory, it is believed that this acute improvementresults at least in part from an immediate increase in skin tone by theself-tanning skin colouring agent. The compositions of the presentinvention have very good acute benefits on application, namely producinggood skin tone without the skin appearing unnatural or orange in effect.

[0019] These and other features, aspects, and advantages of the presentinvention will become evident to those skilled in the art from a readingof the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0020] All weights, measurements and concentrations herein are measuredat 25° C. on the composition in its entirety, unless otherwisespecified.

[0021] Unless otherwise indicated, all percentages of compositionsreferred to herein are weight percentages and all ratios are weightratios.

[0022] Unless otherwise indicated, all molecular weights are weightaverage molecular weights.

[0023] Unless otherwise indicated, the content of all literature sourcesreferred to within this text are incorporated herein in full byreference.

[0024] Except where specific examples of actual measured values arepresented, numerical values referred to herein should be considered tobe qualified by the word “about”.

[0025] The cosmetic compositions of the present invention comprise aself-tanning agent. As used herein, the term “self-tanning agent”includes α-hydroxy aldehydes and ketones such as dihydroxyacetone andstructurally related compounds. This definition includes all such agentsthat are similarly useful in producing or inducing the artificialtanning process in human skin. Accordingly, the compositions of thepresent invention comprise an α-hydroxy aldehyde or ketone of theformula (I):

[0026] wherein R₁ is H, CH₂OH, CHOHCH₂OH, CH(OH)CH(═O), CH(OCH₃)CH(═O),CH(NH₂)CH(═O), or CH(NH-Phenyl)CH(═O); and R₂ is H or CH₂OH.Dihydroxyacetone (DHA) itself may be represented by the followinggeneral structural formula:

[0027] A number of other compounds are already known in the art ascapable of producing or inducing the same artificial tanning process inhuman skin as is produced or induced by DHA. Some of these arestructurally similar to DHA, and include the following:

[0028] Preferably, the self-tanning agent comprises DHA, erythrulose, ormixtures thereof, more preferably DHA. Preferably the compositions ofthe present invention comprise from 0.1% to 10% of the self-tanningagent. More preferable, the compositions of the present inventioncomprise from 1.0% to 3.5%, more preferably still from 1.2% to 2.5% ofthe self tanning agent.

[0029] The cosmetic compositions of the present invention also comprisea branched and/or cross-linked anionic polyelectrolyte polymer. As usedherein, “branched and/or cross-linked anionic polyelectrolyte polymer”includes non-linear polymers in the form of a three-dimensional networkthat is insoluble in water but swellable in water and thus leading tothe production of a chemical gel. The composition according to theinvention can comprise cross-linked units and/or branched units. Thebranched and/or cross-linked anionic polyelectrolyte polymer comprisesat least one monomer possessing a strongly acidic function,co-polymerized with at least one hydroxy alkyl acrylate neutral monomer.

[0030] Preferably, the compositions of the present invention comprise abranched and/or cross-linked anionic polyelectrolyte polymer that is theresult of the copolymerization of its precursor monomers that is carriedout at pH 4.0 or below. Preferably the anionic polyelectrolyte comprisesfrom 30% to 89.9999% by weight of the polyelectrolyte polymer of amonomer having a strongly acidic function. As used herein, the term“monomer having a strongly acidic function” includes monomers having apKa of less than 3. The pKa is measured by titration of the monomerhaving a strongly acidic function with a strong base in aqueous solutionaccording to methods well known in the art. The strongly acidic functionof the monomer containing it is preferably a sulphonic acid function ora phosphonic acid function, partially or totally salified. Non-limitingexamples of monomers having a strongly acidic function group suitablefor use herein include partially or totally salified2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid, partiallyor totally salified styrenesulfonic acid, or mixtures thereof.Preferably, the monomer comprises the partially or totally salifiedalkali metal salt or an ammonium salt of2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulphonic acid.

[0031] Non-limiting examples of the at least one hydroxy alkyl acrylateneutral monomer suitable for use herein include 2-hydroxy-ethylacrylate, 2,3-dihydroxypropyl acrylate, 2-hydroxy-ethyl methacrylate and2,3-dihydroxypropyl methacrylate, or an ethoxylated derivative, with amolecular weight from 400 to 1000 of each of these esters, or mixturesthereof, preferably 2-hydroxy-ethyl acrylate. Polyelectrolyte polymersuseful herein preferably comprise from 9.9999% to 40% by weight of thepolyelectrolyte polymer of the at least one hydroxy alkyl acrylateneutral monomer.

[0032] More preferably, the compositions of the present inventioncomprise a reverse latex polymer comprising a branched and/orcross-linked anionic polyelectrolyte polymer, said polymer comprisingpartially or totally salified2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid,copolymerized with 2-hydroxyethyl acrylate. More preferably still, thepolymer comprises 30% to 89.9999%, preferably 50% to 89.9999%, of themonomer units of partially or totally salified2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid (MPSA) byweight of the polyelectrolyte polymer. Even more preferably, thecross-linked anionic polyelectrolyte polymer comprises, from 58.7% to89.9999% of sodium salt or of ammonium salt of2-methyl-2[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid by weight ofthe polyelectrolyte polymer and from 9.9999% to 40% of 2-hydroxyethylacrylate by weight of the polyelectrolyte polymer.

[0033] The polymers for use in the present invention preferably comprisean anionic polyelectrolyte that is crosslinked and/or branched with adiethylenic or polyethylenic compound at levels of from 0.0002% to 1.3%,preferably from 0.001% to 0.8%, more preferably from 0.01% to 0.6% byweight of the polyelectrolyte polymer. Non-limiting examples ofcrosslinking agents and/or branching agents suitable for use hereininclude ethylene glycol dimethacrylate, sodium diallyloxyacetate,ethylene glycol diacrylate, diallylurea, trimethylolpropane triacrylate,methylene bisacrylamide, or mixtures thereof, preferably methylenebisacrylamide.

[0034] Preferably, the cosmetic compositions of the present inventioncomprise from 0.1% to 2.0% of the branched and/or cross-linked anionicpolyelectrolyte polymer, more preferably from 0.2% to 1.2%, morepreferably still from 0.4% to 0.8%.

[0035] Non-limiting examples of commercially available branched and/orcross-linked anionic polyelectrolyte polymer compositions suitable foruse herein include Simulgel NS™, available from Societe D'Exploitationde Produits Pour Les Industries Chimiques (SEPPIC), Paris, France.

[0036] The compositions of the invention comprise at least onepolyhydric alcohol humectant. Suitable polyhydric alcohols for useherein include polyalkylene glycols and more preferably alkylene polyolsand their derivatives, including propylene glycol, dipropylene glycol,polypropylene glycol, polyethylene glycol and derivatives thereof,sorbitol, hydroxypropyl sorbitol, erythritol, threitol, pentaerythritol,xylitol, glucitol, mannitol, hexylene glycol, butylene glycol (e.g.,1,3-butylene glycol), hexane triol (e.g., 1,2,6-hexanetriol),trimethylol propane, neopentyl glycol, glycerine, ethoxylated glycerineand propoxylated glycerine. Preferred polyhydric alcohols of the presentinvention are polyhydric alcohols with 3 to 9 carbon atoms in themolecule. Suitable polyhydric alcohols include glycerine, butyleneglycol, propylene glycol, dipropylene glycol, polyethylene glycol andderivatives thereof, hexane triol, ethoxylated glycerine andpropoxylated glycerine, or mixtures thereof. More preferred for use inthe present invention is glycerine. Preferably, the compositions of thepresent invention comprise from 5% to 30% humectant, more preferablyfrom 7% to 25%.

[0037] It has been found that polyhydric alcohol humectants aredesirable to counteract the drying effect that self-tanning agents havewhen topically applied, and also to chronically hydrate the skin inorder to improve its skin barrier function. It has also beensurprisingly found that polyhydric alcohol humectant increases thecoloration of skin by the self tanning agent claimed (e.g. DHA), evenwhen present at level lower than 20%. The improved coloration effect canbe shown by measuring the skin coloration (e.g. on the forearm) obtainedwith a product according to the invention versus the same productwithout a polyhydric alcohol humectant. Skin coloration measurements canbe made according to conventional means, for example using a Minolta™Chromameter CR-300.

[0038] This increased coloration effect was particularly noticeable atlevels of polyhydric alcohol humectant from 5 to 15% by weight,preferably from 8 to 13% and for self-tanning agent levels below levelsused in conventional marketed self tanning products, i.e. levels at orbelow 5%, preferably at or below 4%, more preferably at or below 3%.Using lower levels of skin tanning agent also benefits the skin as thesetend to damage skin over repeated uses. Whilst not wishing to be boundby theory, Applicant believes that the polyhydric alcohol humectant(e.g. glycerine) increase the water content of the skin horny layer,which in turn favours the self tanning process. It is also believed thatpolyhydric alcohol humectants may improve the skin condition, minimisingany areas of dry or compromised skin. This is desirable as dry skinareas have uneven uptake of colour resulting in a blotchy or patchyresult.

[0039] The compositions of the present invention further have a pH offrom 3.5 to 4.5, preferably from 3.7 to 4.2. It has surprisingly beenfound that the polymers as defined in the present invention are stableat these low pHs, and in the presence of self-tanning agents. It hasalso surprisingly been found that by combining the polymers of thepresent invention with self-tanning agents at low pHs, stable emulsionscan be formed that deliver relatively high proportions of activeself-tanning agent to the skin following topical application, withoutthe discoloration of the composition often associated with compositionscomprising self-tanning agents. Without wishing to be bound by theory,it is believed that the combination of the polymers herein, and the lowpH of the composition prevent the formation of methyl glyoxal, adegradation product of DHA. It has been suggested in U.S. Pat. No.6,231,837 B1 that methyl glyoxal is responsible for the development ofdiscoloration in formulations comprising DHA, and is also responsiblefor the production of an undesirable orange pigmentation when DHA isapplied to the skin and is not present in a stabilised form. This may bethe reason why the compositions of the present invention deliverself-tanning agents to the skin in a form that provides a naturaltanning appearance, without the associated orange discoloration oftenassociated with compositions containing self-tanning agents.

[0040] The compositions of the present invention may additionallycomprise other humectants, including sodium 2-pyrrolidone-5-carboxylate(NaPCA); guanidine; glycolic acid and glycolate salts (e.g. ammonium andquaternary alkyl ammonium); aloe vera in any of its variety of, forms(e.g., aloe vera gel); hyaluronic acid, precursors and derivativesthereof (e.g., glucosamine and salt derivatives such as sodiumhyaluronate); lactamide monoethanolamine; acetamide monoethanolamine;urea; and mixtures thereof.

[0041] The compositions of the present invention may further comprisefrom 0.1% to 15% of a skin care active that is stable in self-tanningsystems. Preferably, the compositions of the present invention comprisefrom 0.25% to 5% of a skin care active. Stable skin care actives usefulherein include betaine and its derivatives, tocopherol esters, skinlipids, or mixtures thereof. Incorporation of skin care actives in thepresent compositions enhances the skin benefit properties by providingreduced water loss and/or providing a desquamatory, keratolytic andrejuvenating effect when topically applied.

[0042] One class of skin care actives suitable for use herein are thebetaines. Betaines suitable for use herein include those with amolecular weight of from greater than 75 to less than 260, preferablyfrom greater than 75 to less than 200 and more preferably from greaterthan 75 to less than 180.

[0043] Betaines useful in the present invention comprise quaternaryammonium salts represented by the general formula (II) below:

[0044] wherein R₁, R₂, and R₃ are independently selected from —H, —CH₃,—CH₂CH₃, and [—CH₂CH(OH)R₄, wherein R₄ is selected from —H, and C1 to C4alkanes]; and wherein n=an integer from 1 to 3, preferably 1. PreferablyR₁, R₂, and R₃ are all —CH₃, and n is 1; or R₁, R₂, and R₃ are all —CH₃,and n is 2; or R₁ and R₂ are —CH₃, R₃ is —H, and n is 1; or R₁ is —CH₃,R₂ and R₃ are —H, and n is 1; or R₁ and R₂ are [—CH₂CH(OH)R₄, R₄ is —Hor —CH₃], R₃ is —H, and n is 1.

[0045] Further examples of betaines and derivatives thereof suitable foruse in the present invention include betaines conforming to formula(II), wherein any two of R₁, R₂, and R₃ are independently selected from—H, and —CH₃, and the third moiety of R₁, R₂, and R₃ is selected from—(CH₂)mCH₃ wherein m is 4 or 5; and wherein n=an integer from 1 to 3,preferably 1; preferably wherein R₁ and R₂ are —CH₃, R₃ is —(CH₂)mCH₃wherein m is 4, and n is 1.

[0046] Another class of betaine derivatives suitable for use in thepresent invention include cholines conforming to the general formula(III):

[0047] wherein R₁, R₂, R₃ R₄ are defined as in part (i) above; andwherein m is an integer from 0 to 2, and R₅ is selected from PO₄, SO₄and SO₃, and R₆ is selected from H or OH. Preferred are cholines whereinR₁, R₂, and R₃ are —CH₃; m is 0; R₆ is H and R₅ is PO₄; or taurineswherein R₁, R₂, and R₃ are —CH₃; m is 0; and R₅ is SO₃, R₆ is H, or R₁,R₂, and R₃ are —CH₃; m is 1; R₆ is OH and R₅ is SO₃.

[0048] Further betaine derivatives suitable for use in the presentinvention are those comprising proline, carnitine, trimethylamineoxide,tricine, dimethyl proline and mixtures thereof.

[0049] Preferred for use herein are betaine or derivatives thereofcomprising trimethylglycine, dimethyl glycine, sarcosine, trimethylalanine, tricine, dimethyl proline, bicine, gamma-butyro betaine,trimethylamineoxide, proline, carnitine, and mixtures thereof, morepreferably comprising trimethylglycine, tricine and dimethyl glycine;and mixtures thereof.

[0050] Non-limiting examples of preferred betaines or derivatives foruse herein are identified immediately above. Non-limiting examples ofpreferred betaines or derivatives include trimethylglycine hydrate,available as TEGOCARE AP (RTM), from T. H. Goldschmidt (Germany),proline, available as proline, from Huls-Degussa (Germany), bicine,available as bicine, from Sigma Chemical (USA), and dimethylglycine,available as dimethylglycine from Sigma Chemical (USA).

[0051] Another class of skin care actives suitable for use hereinincludes the tocopherol esters, materials formed as a result of thecondensation reaction between tocopherol and carboxylic acids. As usedherein, “tocopherol esters” includes those materials conforming to thegeneral formula (IV):

[0052] wherein, R═OO is selected from linear, branched and cycliccarboxylic acids, preferably acetic acid, linoleic acid, nicotinic acid,oleic acid, or mixtures thereof. More preferably, the skin care activecomprises tocopherol acetate, tocopherol nicotinate, or mixturesthereof. Non-limiting examples of commercially available tocopherolesters include tocopherol nicotinate from Ennagram UK Ltd, London, UK

[0053] A further class of skin care actives suitable for use in thepresent invention are the skin lipids. Skin lipids perform an integralfunction of maintaining the water holding ability of the stratumcorneum, regulating skin health. Non-limiting examples of skin lipidssuitable for use herein include ceramides, cholesterols, fatty acids, ormixtures thereof. Ceramides, the primary component of skin lipids, andare comprised of sphingolipids consisting of a long chain amino alcohol(sphingosine or one of it's derivatives) to which a long chain fattyacid is linked via an amide bond. Natural or synthetic sources can beused, as can pseudo-ceramides. Preferably, the skin care active hereincomprises ceramide, cholesterol, sphingosine, or mixtures thereof.Non-limiting examples of commercially available blends of skin lipidssuitable for use herein include SK Influx from Cosmoferm.

[0054] The compositions of the present invention may further comprise anatural gum thickener. It has been found that the rheology and stabilityof the present compositions can be suitably modified and improved by theaddition of low levels of natural gum thickeners, without thecompositions becoming too stringy, or tacky. Natural gum thickenerssuitable for use herein include xanthan gum, guar gum or itsderivatives, chitosan, alginates, carragenan, locust bean gum,sclerotium, pectin, starches or their derivatives, or mixtures thereof,preferably xanthan gum. Where present, the natural gum thickeners arepreferably present at levels of from 0.05% to 3%, more preferably from0.05% to 1%, more preferably still from 0.05% to 0.5%.

[0055] The compositions of the invention are preferably formulated so asto have a product viscosity of at least 4,000 mPa.s and preferably inthe range from 4,000 to 300,000 mPa.s, more preferably from 8,000 to250,000 mPa.s and especially from 10,000 to 200,000 mPa.s and even moreespecially from 20,000 to 100,000 mPa.s (25° C., neat, Brookfield RVT,T-C Spindle at 5 rpms and Heliopath Stand). The compositions of thepresent invention may be formulated as an emulsion.

[0056] The cosmetic compositions herein are preferably in the form of awater-in-oil or oil-in-water emulsion. More preferably the cosmeticcompositions herein are oil-in-water emulsions wherein the compositioncomprises one or more oil phases in an aqueous continuous phase, eachoil phase comprising a single oily component or a mixture of oilycomponents in miscible or homogeneous form. Different oil phases containdifferent materials, or different combinations of materials, from eachother. The total level of oil phase components in the compositions ofthe invention is typically from 0.1% to 60%, preferably from 1% to 30%,more preferably from 3% to 20% and most preferably from 5% to 15%.

[0057] In preferred embodiments, the oil phase preferably comprises oilycomponents such as a natural or synthetic oils selected from mineral,vegetable, and animal oils, fats and waxes, fatty acid esters, fattyalcohols, fatty acids and mixtures thereof. Preferred for use herein arefor example, saturated and unsaturated fatty alcohols such as behenylalcohol, cetyl alcohol and stearyl alcohol and hydrocarbons such asmineral oils or petrolatum.

[0058] The present compositions may further comprise a silicone phase.The silicone phase can comprise one or more silicone components such assilicone fluids, gums, and mixtures thereof. The, or each, siliconephase generally comprises from 0.1% to 20%, preferably from 0.2% to 10%,more preferably from 0.3% to 5%, of the composition.

[0059] Silicone components can be fluids, including straight chain,branched and cyclic silicones. Suitable silicone fluids useful hereininclude silicones inclusive of polyalkyl siloxane fluids, polyarylsiloxane fluids, cyclic and linear polyalkylsiloxanes, polyalkoxylatedsilicones, amino and quaternary ammonium modified silicones,polyalkylaryl siloxanes or a polyether siloxane copolymer and mixturesthereof. The silicone fluids can be volatile or non-volatile.

[0060] The silicone components can also comprise silicone gums. The term“silicone gum” herein includes high molecular weight silicones having aweight average molecular weight in excess of about 200,000 andpreferably from about 200,000 to about 4,000,000. Included arenon-volatile polyalkyl and polyaryl siloxane gums. In preferredembodiments, a silicone oil phase comprises a silicone gum or a mixtureof silicones including the silicone gum.

[0061] Useful herein are silicone/gum fluid blends. Preferredsilicone-gum fluid blend based component for use in the compositionsherein is a dimethiconol gum having a molecular weight of from 200,000to 4,000,000 along with a silicone fluid carrier with a viscosity of0.65 to 100 mm².s⁻¹. An example of this silicone component is DowCorning Q2-1503 (85% 5 mm².s⁻¹ Dimethicone Fluid/15% Dimethiconol) andDow Corning Q2-1501 available from Dow Corning.

[0062] The topical compositions of the present invention preferablycomprise emollient materials including branched chain hydrocarbonshaving an weight average molecular weight of from 100 to 15,000,preferably from 100 to 1000; compounds of formula V:

[0063] wherein R¹ is selected from H or CH₃, R², R³ and R⁴ areindependently selected from C₁-C₂₀ straight chain or branched chainalkyl, and x is an integer of from 1-20; and compounds having theformula VI:

[0064] wherein R⁵ is selected from optionally hydroxy or C₁-C₄ alkylsubstituted benzyl and R₆ is selected from C₁-C₂₀ branched or straightchain alkyl; and mixtures thereof.

[0065] Suitable branched chain hydrocarbons for use herein includeisododecane, isohexadecane, isoeicosane, isooctahexacontane,isohexapentacontahectane, isopentacontaoctactane, and mixture thereof.Suitable ester emollient materials of Formula (VI) include but are notlimited to C12-15 alkyl benzoates.

[0066] Preferred emollients for use herein are isohexadecane, isononylisononanoate, methyl isostearate, isopropyl isostearate, and mixturesthereof. A further emollient suitable for use in the composition of thepresent invention is petrolatum.

[0067] The emollient material is preferably present in the compositionsat a level of from about 0.1% to about 10%.

[0068] The present compositions herein may comprise an emulsifier and/orsurfactant, generally to help disperse and suspend the discontinuousphase within the continuous phase. For convenience hereinafteremulsifiers will be referred to under the term ‘surfactants’, thus‘surfactant(s)’ will be used to refer to surface active agents whetherused as emulsifiers or for other surfactant purposes such as skincleansing. Known or conventional surfactants can be used in thecomposition, provided that the selected agent is chemically andphysically compatible with essential components of the composition, andprovides the desired characteristics.

[0069] The compositions of the present invention preferably comprisefrom 0.05% to 15% of a surfactant or mixture of surfactants. The exactsurfactant or surfactant mixture chosen will depend upon the pH of thecomposition and the other components present. Surfactants suitable foruse herein include non-ionic, cationic, anionic, zwitterionic,amphoteric surfactants, or mixtures thereof.

[0070] Preferred surfactants are nonionic. Among the nonionicsurfactants that are useful herein are those that can be broadly definedas condensation products of long chain alcohols, e.g. C₈-₃₀ alcohols,with sugar or starch polymers, i.e., glycosides. Preferred examplesinclude a mixture of cetearyl glucosides and cetearyl alcohols such asthose commercially available as Montanov 68™ from Seppic and EmulgadePL68/50™ available from Henkel.

[0071] Other useful nonionic surfactants include the condensationproducts of alkylene oxides with fatty acids (i.e. alkylene oxide estersor diesters of fatty acids). Other nonionic surfactants are thecondensation products of alkylene oxides with fatty alcohols (i.e.alkylene oxide ethers of fatty alcohols). Still other nonionicsurfactants are the condensation products of alkylene oxides with bothfatty acids and fatty alcohols [i.e. wherein the polyalkylene oxideportion is esterified on one end with a fatty acid and etherified (i.e.connected via an ether linkage) on the other end with a fatty alcohol].Still other useful nonionic surfactants include polyhydroxy fatty acidamide surfactants, which are described in more detail in WO98/04241.

[0072] Another emulsifier useful herein are fatty acid ester blendsbased on a mixture of sorbitan or sorbitol fatty acid ester and sucrosefatty acid ester, the fatty acid in each instance being preferablyC₈-C₂₄, more preferably C₁₀-C₂₀. The preferred fatty acid esteremulsifier is a blend of sorbitan or sorbitol C₁₆-C₂₀ fatty acid esterwith sucrose C₁₀-C₁₆ fatty acid ester, especially sorbitan stearate andsucrose cocoate. This is commercially available from ICI under the nameArlatone 2121™.

[0073] Preferred among the nonionic surfactants are those selected fromthe group consisting of cetearyl glucosides, cetearyl alcohols, PEG-100stearate, sorbitan stearate and mixtures thereof.

[0074] Emulsions of the present invention may include a siliconecontaining emulsifier or surfactant. A wide variety of siliconeemulsifiers are useful herein. These silicone emulsifiers are typicallyorganically modified organopolysiloxanes, also known to those skilled inthe art as silicone surfactants. Useful silicone emulsifiers includedimethicone copolyols. Other examples include alkyl-modified dimethiconecopolyols, i.e., compounds that contain C₂-C₃₀ pendant side chains.Still other useful dimethicone copolyols include materials havingvarious cationic, anionic, amphoteric, and zwitterionic pendantmoieties.

[0075] The composition of the present invention comprises water.Preferably, water comprises from 30% to 85% by weight of thecomposition, more preferably 50% to 75% by weight of the composition.

[0076] The compositions of the present invention can further compriseoptional ingredients. Optional ingredients are well known in the art,and can be added without reacting with and altering the chemistrytherein. Optional ingredients include additional actives, neutralizingagents, sunscreening agents and mixtures thereof.

[0077] The cosmetic compositions of the present invention can beformulated in a form suitable for topical application. Non-limitingexamples of such forms include self-tanning compositions, topicalcompositions, sprays, aerosol sprays, spray gels, lotions, creams andmousses. Preferably, the cosmetic compositions of the present inventionare in the form of a self-tanning composition or a lotion.

[0078] Alternatively, the cosmetic compositions of the present inventionmay be used in combination with a substrate to form a skin care kit. Theskin care kits of the present invention comprise the cosmeticcompositions herein, and a substrate. Non-limiting examples ofsubstrates useful herein include wet wipes, towlettes, foam sponges,roller ball delivery systems and the like. When used in this form, thesubstrate may be impregnated, coated, or soaked with the compositionsherein. Alternatively, the compositions herein may be applied to thesubstrate by the consumer immediately prior to application to the skin.The skin care kits herein are desirable to prevent the accidentalapplication of the cosmetic composition to areas of the body where it isnot required or desired.

[0079] The compositions of the present invention are useful forregulating skin condition and enhancing skin tone. Such regulation ofskin condition can include cosmetic prophylactic and therapeuticregulation. It may also include providing a more noticeable improvement,both tactile and visual, in the appearance and feel of the skin of amammal. For example, such regulating methods are directed to making theskin feel softer, reducing the appearance of fine lines and wrinkles,and improving skin health. Also, such methods provide an enhancement ofskin tone. The compositions of the present invention enhance skin toneby imparting a natural-looking tan to the skin of a consumer followingtopical application, without the appearance of an orange colour. This isbelieved to be due to the improved stabilisation of the self-tanningagent in the compositions, and increased delivery of the self-tanningagent in its active form.

[0080] Regulating skin condition involves topically applying to the skina safe and effective amount of a composition of the present invention.In a preferred embodiment, the composition is chronically applied to theskin. By “chronic topical application” is meant continued topicalapplication of the composition over an extended period during thesubject's lifetime, preferably for a period of at least about one week,more preferably for a period of at least about one month, even morepreferably for at least about three months, even more preferably for atleast about six months, and more preferably still for at least about oneyear. While benefits are obtainable after various maximum periods of use(e.g., five, ten or twenty years), it is preferred that chronicapplication continue throughout the subject's lifetime. Typicallyapplications would be on the order of about once per day over suchextended periods, however application rates can vary from about once perweek up to about three times per day or more.

[0081] A wide range of quantities of the compositions of the presentinvention can be employed to provide a skin appearance and/or feelbenefit. Quantities of the present compositions, which are typicallyapplied per application, are, in mg composition/cm² skin, from 0.1mg/cm² to 30 mg/cm². A particularly useful application amount is 0.5mg/cm² to 20 mg/cm².

[0082] Regulating skin condition is preferably practiced by applying acomposition which is intended to be left on the skin for some aesthetic,cosmetic, prophylactic, therapeutic or other benefit (i.e., a “leave-on”composition). After applying the composition to the skin, it ispreferably left on the skin for a period of at least 15 minutes, morepreferably at least 30 minutes, even more preferably at least 1 hour,still more preferably for at least several hours, e.g., up to 12 hours.

[0083] Another approach to ensure a continuous exposure of the skin toat least a minimum level of the skin care active is to apply thecompound by use of a patch applied, e.g., to the face. The patch can beocclusive, semi-occlusive or non-occlusive and can be adhesive ornon-adhesive. The composition can be contained within the patch or beapplied to the skin prior to application of the patch. The patch canalso include additional actives such as chemical initiators forexothermic reactions such as those described in U.S. Pat. Nos.5,821,250, 5,981,547, and 5,972,957. The patch is preferably left on theskin for a period of at least 5 minutes, more preferably at least 15minutes, more preferably still at least 30 minutes, even more preferablyat least 1 hour, still more preferably at night as a form of nighttherapy.

[0084] The compositions of the present invention may be manufacturedaccording to a certain method. The method for manufacturing thecompositions herein comprises the steps of forming a premix comprisingthe branched and/or cross-linked anionic polyelectrolyte polymer at atemperature of from 50° C. to 70° C. Subsequently, said premix is cooledto a temperature of less than 40° C. and the self-tanning agent isadded. It is desirable to form the compositions of the present inventionin this way to maintain the stability of the self-tanning agent duringmanufacture and subsequent storage. Without wishing to be bound bytheory, it is believed that adding the self-tanning agent to a premixalready comprising the branched and/or cross-linked anionicpolyelectrolyte polymer at a temperature of less than 40° C. inhibitsthe potential for the self-tanning agent to react with the polymer andother ingredients therein, thereby enhancing the amount of activeself-tanning agent present in the composition.

Examples I-V

[0085] Example 1 Example 2 Example 3 Example 4 Example 5 INGREDIENTS(w/w %) (w/w %) (w/w %) (w/w %) (w/w %) DEIONISED QS QS QS QS QS WATERGLYCERINE 7.0 10.0 10.0 10.0 15.0 SK INFLUX¹ — — — 1.0 1.0 TOCOPHEROL —3.0 — — — NICOTLNATE² VITAMIN E 0.25 — 0.5 — 0.25 ACETATE ISOHEXADECANE3.0 3.0 3.0 3.0 3.0 ISOPROPYL 1.50 1.50 1.50 1.50 1.50 ISOSTEARATECOCONUT OIL 0.2 0.2 0.2 0.2 0.2 FRACTIONATED PETROLATUM 2.0 2.0 2.0 2.02.0 SIMUGEL NS³ 1.0 1.5 1.5 1.5 2.0 XANTHAN GUM 0.1 0.1 0.1 0.2 0.2STEARYL 0.6 0.6 0.6 0.6 0.6 ALCOHOL CETYL ALCOHOL 0.5 0.5 0.5 0.5 0.5BEHENYL — 0.4 0.4 0.4 0.4 ALCOHOL PEG-100 STEARATE 0.1 0.1 0.1 0.1 0.1EMULGADE⁴ 0.2 0.2 0.2 0.2 0.2 NYLONPOLY — 1.0 — 1.0 1.0 WL10⁵ DRY FLOPLUS⁶ 0.5 1.0 0.5 1.0 1.0 MICROTHENE⁷ 0.5 — 0.5 — — DHA⁸ 1.0 1.5 2.5 1.55.0 ERYTHRULOSE⁹ — — — 0.5 — ETHYL PARABEN 0.15 0.15 0.15 0.15 0.15PROPYL PARABEN 0.07 0.07 0.07 0.07 0.07 DISODIUM EDTA 0.1 0.1 0.1 0.10.1 BENZYL ALCOHOL 0.25 0.25 0.25 0.25 0.25 DC 1503 1.0 1.0 1.0 1.0 1.0PERFUME 0.2 0.2 0.2 0.2 0.2

[0086] The compositions are made as follows:

[0087] A water phase is prepared by admixing all water solubleingredients (including xanthan gum), except DHA and Erythrulose, inwater and heating to 80° C. A second premix is prepared by admixing ofthe oil soluble ingredients except the silicone oil (DC 1503) andheating also to 80° C. The oil phase is added to the water phase andsheared to form an emulsion.

[0088] The emulsion is cooled to 60° C. and the polymeric thickener(Simugel NS) is then added. At 45-50° C. the benzyl alcohol and DC1503,and particles are added and the resulting product is sheared to ensureparticle dispersion, de-agglomeration and homogeneity. The compositioncan then be cooled to below 40° C. and DHA, Erythrulose and perfume canbe added. The product can then be prepared for packaging.

[0089] All documents cited in the Detailed Description of the Inventionare, in relevant part, incorporated herein by reference; the citation ofany document is not to be construed as an admission that it is prior artwith respect to the present invention.

[0090] While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A cosmetic composition comprising: a) aself-tanning agent conforming to the general formula;

wherein R₁ is H, CH₂OH, CHOHCH₂OH, CH(OH)CH(═O), CH(OCH₃)CH(═O),CH(NH₂)CH(═O), or CH(NH-Phenyl)CH(═O); and R₂ is H or CH₂OH; and b) abranched and/or cross-linked anionic polyelectrolyte polymer, saidanionic polyelectrolyte polymer comprising; i) from about 58.7% to about89.9999% by weight of the polyelectrolyte polymer of a monomercomprising a strongly acidic function; ii) from about 9.9999% to about40% by weight of the polyelectrolyte polymer of at least one hydroxyalkyl acrylate neutral monomer; and iii) from about 0.0002% to about1.3% by weight of the polyelectrolyte polymer of a diethylenic orpolyethylenic cross-linking agent; c) a polyhydric alcohol humectant;said composition further having a pH of from about 3.5 to about 4.5. 2.The cosmetic composition according to claim 1 wherein the stronglyacidic function of said monomer of part i) comprises partially andtotally salified sulphonic acid function, partially and totally salifiedphosphonic acid function and mixtures thereof.
 3. The cosmeticcomposition according to claim 1 wherein the neutral monomer comprises2-hydroxyethylacrylate, 2,3-dihydroxypropyl acrylate, 2-hydroxy-ethylmethacrylate and 2,3-dihydroxypropyl methacrylate, or an ethoxylatedderivative having a molecular weight of from 400 to 1000 and mixturesthereof.
 4. The cosmetic composition according to claim 3 wherein theneutral monomer comprises 2-hydroxy ethyl acrylate.
 5. The cosmeticcomposition according to claim 1 wherein the cross-linking and branchingagents comprise ethylene glycol dimethacrylate, sodiumdiallyloxyacetate, ethylene glycol diacrylate, diallylurea,trimethylolpropane triacrylate, methylene bisacrylamide and mixturesthereof.
 6. The cosmetic composition according to claim 5 wherein thecross-linking and branching agents comprise methylene bisacrylamide. 7.The cosmetic composition according to claim 1 wherein the branched andcross-linked anionic polyelectrolyte polymers comprise: i) from about58.7% to about 89.9999% by weight of the polyelectrolyte polymer of thepartially and/or totally salified alkali metal salt or ammonium salt of2-methyl-2-[(1-oxo-2-propenyl)-1-propanesulphonic acid; ii) from about9.9999% to about 40% by weight of the polyelectrolyte polymer of2-hydroxyethylacrylate; and iii) from about 0.0002% to about 1.3% byweight of the polyelectrolyte polymer of methylene bisacrylamide.
 8. Thecosmetic composition according to claim 7 wherein the branched andcross-linked anionic polyelectrolyte polymers are reverse latexpolymers.
 9. The cosmetic composition according to claim 1 comprisingfrom about
 0. 1% to about 2% of branched and cross-linked anionicpolyelectrolyte polymers.
 10. The cosmetic composition according toclaim 1 comprising from about 0.1% to about 10% of the self-tanningagent.
 11. The cosmetic composition according to claim 1 wherein theself-tanning agent comprises dihydroxyacetone, erythrulose and mixturesthereof.
 12. The cosmetic composition according to claim 1 wherein thepH of the composition is from about 3.7 to about 4.2.
 13. The cosmeticcomposition according to claim 1 comprising from about 5% to about 30%by weight of the composition of a polyhydric alcohol humectant.
 14. Thecosmetic composition according to claim 13 comprising from about 5% toabout 15% by weight of the composition of a polyhydric alcoholhumectant.
 15. The cosmetic composition according to claim 1 whereinsaid polyhydric alcohol humectant is selected from the group consistingof propylene glycol, dipropylene glycol, polypropylene glycol,polyethylene glycol and derivatives thereof, sorbitol, hydroxypropylsorbitol, erythritol, threitol, pentaerythritol, xylitol, glucitol,mannitol, hexylene glycol, butylene glycol, hexane triol, trimethylolpropane, neopentyl glycol, glycerine, ethoxylated glycerine andpropoxylated glycerine, and mixtures thereof.
 16. The cosmeticcomposition according to claim 15 wherein said polyhydric alcoholhumectant comprises glycerine.
 17. The cosmetic composition according toclaim 1 further comprising a skin care active.
 18. The cosmeticcomposition according to claim 17, wherein said skin care activecomprises betaine and its derivatives, tocopherol esters, skin lipidsand mixtures thereof.
 19. The cosmetic composition according to claim18, wherein said skin care active comprises trimethyl glycine,tocopherol nicotinate, tocopherol acetate, ceramide, cholesterol,sphingosineand mixtures thereof.
 20. The cosmetic composition accordingto claim 17 comprising from about 0.1% to about 15% of said skin careactive.
 21. The cosmetic composition according to claim 1 furthercomprising a natural gum thickener.
 22. The cosmetic compositionaccording to claim 21 comprising from about 0.05% to about 3% by weightof the composition of a natural gum thickener.
 23. The cosmeticcomposition according to claim 21 wherein said natural gum thickenercomprises xanthan gum, guar gum or its derivatives, chitosan, alginates,carageenan, locust bean gum, sclerotium, pectin, starches or theirderivativesand mixtures thereof.
 24. The cosmetic composition accordingto claim 23 wherein said natural gum thickener comprises xanthan gum.25. The cosmetic composition according to claim 1, wherein the cosmeticcomposition is in the form of an emulsion.
 26. The cosmetic compositionaccording to claim 25 wherein the cosmetic composition is in the form ofan oil-in-water emulsion.
 27. The cosmetic composition according toclaim 26 wherein the oil phase comprises from about 0.1% to about 60% byweight of the composition.
 28. A method of regulating skin conditioncomprising topically applying the composition according to claim 1 tothe skin in an amount of from 0.1 mg/cm² to 30 mg/cm².
 29. An article ofcommerce comprising a container, a skin care composition containing aself-tanning agent and a substrate to provide provides the user tochange the appearance of the skin said composition comprising: a) aself-tanning agent conforming to the general formula;

wherein R₁ is H, CH₂OH, CHOHCH₂OH, CH(OH)CH(═O), CH(OCH₃)CH(═O),CH(NH₂)CH(═O), or CH(NH-Phenyl)CH(═O); and R₂ is H or CH₂OH; and b) abranched and/or cross-linked anionic polyelectrolyte polymer, saidanionic polyelectrolyte polymer comprising; i) from about 58.7% to about89.9999% by weight of the polyelectrolyte polymer of a monomercomprising a strongly acidic function; ii) from about 9.9999% to about40% by weight of the polyelectrolyte polymer of at least one hydroxyalkyl acrylate neutral monomer; and iii) from about 0.0002% to about1.3% by weight of the polyelectrolyte polymer of a diethylenic orpolyethylenic cross-linking agent; c) a polyhydric alcohol humectant;said composition further having a pH of from about 3.5 to about 4.5. 30.A method of manufacturing the composition according to claim 1comprising the steps of forming a premix comprising said branched and/orcross-linked anionic polyelectrolyte polymer at a temperature of fromabout 50° C. to about 70° C., cooling said premix to a temperature ofless than about 40° C. and adding said self-tanning agent.